In order to control helicopters, it is necessary to be able to control the angle of attack of the main rotor blades. In most helicopters, this adjustability is provided by a swash plate assembly. The angle of the swash plate is changed through control rods that are moved by the pilot's input to the cyclic and collective controls. The swash plate assembly is a complex mechanical assembly that undergoes tremendous stress at very high speed and is thus subject to severe maintenance requirements. There is thus a need for alternative means of controlling the rotor blade attack angle without the use of a swash plate assembly.